Hard to believe that it's been 25 years today.   I was a grade-school kid who had moved to Tampa, Florida when this happened, and still remember it like it was yesterday.  

We drove to Cape Canaveral to see a couple of Shuttle launches live - and I remember from Tampa, even though it was over a hundred miles away, you could see launches and rocket trails in the distance when one would go up, kind of like a much-larger, faster, and straight-up version of the contrails you see when a jet goes by.   Our school was kind of an open campus, you'd walk out of the classroom into the schoolyard - and being the space-geek I was at the time, even though they would watch launches in-class, I still asked to go to the restroom or made up some kind of excuse that would get me outside to watch it in person where it was much cooler - and seemed more "real".     I saw the far-away version of what this video shows, knew something terrible had happened - ran back to class to find everyone glued to the screen:

There was supposed to be a State Of The Union that night, but President Reagan scrapped it in favor of addressing the nation:

Do you remember where you were that day?   Or if 1986 was before your time - do you remember the Columbia disaster in 2003?